Vertebral fracture severity assessment on anteroposterior radiographs with a new semi-quantitative technique.

We developed a new tool to assess the severity of osteoporotic vertebral fracture using radiographs of the spine. Our technique can be used in patient care by helping to stratify patients with osteoporotic vertebral fractures into appropriate treatment pathways. It can also be used for research purposes. PURPOSE: The aim of our study was to propose a semi-quantitative (SQ) grading scheme for osteoporotic vertebral fracture (OVF) on anteroposterior (AP) radiographs. METHODS: On AP radiographs, the vertebrae are divided into right and left halves, which are graded (A) vertical rectangle, (B) square, (C) traverse rectangle, and (D) trapezoid; whole vertebrae are graded (E) transverse band or (F) bow-tie. Type A and B were compared with normal and Genant SQ grade 1 OVF, Type C and D with grade 2 OVF, and Type E and F with grade 3 OVF. Spine AP radiographs and lateral radiographs of 50 females were assessed by AP radiographs SQ grading. After training, an experienced board-certified radiologist and a radiology trainee assessed the 50 AP radiographs. RESULTS: The height-to-width ratio of the half vertebrae varied 1.32-1.48. On lateral radiographs, 84 vertebrae of the 50 patients had OVFs (38 grade 1, 24 grade 2, and 22 grade 3). On AP radiographs, the radiologist correctly assigned 84.2%, 91.7%, and 77.2% and the trainee correctly assigned 68.4%, 79.2%, and 81.8% of grade 1, 2, and 3 OVFs, respectively. Compared with lateral radiographs, the radiologist had a weighted Kappa of 0.944 including normal vertebrae and 0.883 not including normal vertebrae, while the corresponding Kappa values for the trainee were 0.891 and 0.830, respectively. CONCLUSION: We propose a new semi-quantitative grading system for vertebral fracture severity assessment on AP spine radiographs.

CT detects more osteoporotic endplate depressions than radiograph: a descriptive comparison of 76 vertebrae.

This study analyzed elderly women who had chest radiograph and chest CT with indications other than spine disorders. Using CT images as reference, the study demonstrates that radiograph can miss a high portion of mild endplate depression. Detection of endplate depression is confounded by the limitation of projectional overlay for radiograph. INTRODUCTION: The definition of radiographic OVF (osteoporotic vertebral fracture) remains controversial. Some authors suggest all OVFs should demonstrate endplate fracture/depression on radiograph. Using CT image as the reference, our study tests the hypothesis that a considerable portion of endplate depressions not seen on radiograph can be detected on CT. METHODS: We retrospectively analyzed 46 female cases (age: 67-94 years) who had both chest radiography and chest CT with indications other than spine disorders. Sixty-six "vertebrae of interest" were identified on radiograph; then, CT images were read side-by-side with lateral chest radiograph. RESULTS: Thirty-eight vertebrae (38/66) had anterior wedging deformity with height loss of < 20% while without radiographic endplate depression. Among them, 28 vertebrae had endplate depression and 8 vertebrae had no endplate depression on CT, while 2 vertebrae with "very" minimal deformity were read as normal on CT. In 9 vertebrae (9/66) with anterior wedging and height loss of ≥ 20%, all had additional endplate depression seen on CT. Five vertebrae (5/66) had ambiguous endplate depression on radiograph, 3 had endplate depression on CT while the other 2 vertebrae in one patient were false positive due to X-ray projection. There were 14 short height vertebrae (14/66) where middle and anterior heights were reduced to the same extent while did not show apparent anterior wedging or bi-concaving. Four cases each had one short height vertebra, and all had endplate depression on CT. Another 4 cases had 2, 2, 3, and 3 adjacent short height vertebrae, respectively, and all did not show endplate depression on CT. In addition, inspection of spine CT showed 10 vertebrae in 9 cases appeared normal on radiograph while demonstrated endplate depression on CT. CONCLUSION: With CT images as reference, radiograph can miss a high portion of mild endplate depressions.

Elderly males with or without existing osteoporotic vertebral fracture have much lower future vertebral fracture risk than elderly females: the MrOS (Hong Kong) year-4 follow-up spine radiograph study.

MrOS (Hong Kong)'s year-4 follow-up shows, for subjects at baseline without vertebral deformity (VD) and endplate or/and cortex fracture (ECF), the VD progression/new VD rate during follow-up in males was half of our paired MsOS (Hong Kong) study's results. For those with VD or ECF, the VD progression/new VD was less than one sixth of females' rate. INTRODUCTION: This study documents MrOS (Hong Kong)'s year-4 follow-up, and the results are compared with the MsOS (Hong Kong) study. Of elderly females with Genant's grade-0, -1, -2, and -3 VD, at year-4 follow-up, 4.6%, 8%, 10.6%, and 28.9% had at least one VD progression or incident VD, respectively. METHODS: Spine radiographs of 1500 Chinese males with baseline (mean age 71.7 years, range 65-91 years) and year-4 follow-up were evaluated according to Genant's VD criteria and ECF (non-existent, ECF0; or existent, ECF1). Grade-2 VDs were divided into mild (VD2m, 25-34% height loss) and severe (VD2s, 34-40% height loss) subgroups. Study subjects were graded into eight categories: VD0/ECF0, VD1/ECF0, VD2m/ECF0, VD0/ECF1, VD1/ECF1, VD2m/ECF1, VD2s/ECF1, and VD3/ECF1. With an existing VD, a further height loss of ≥ 15% was a VD progression. A new VD incident was a change from grade-0 to grade-2/3, or to grade-1 with ≥ 10% height loss. RESULTS: Of subjects with Genant's grade-0, 2.05% (25/1219) developed at least one VD progression or/and new VD, while of subjects with Genant's grade-1, -2, and -3 VD, only 2% (3/149), 3.1% (3/96), and 2.8% (1/36) developed at least one VD progression/new VD, respectively. Among the three ECF0 groups, there was a significant difference in new ECF incidence, with VD0/ECF0 being the lowest and VD2m/ECF0 being the highest. CONCLUSION: VD progression/new VD is much less common in elderly men than in elderly women. Vertebrae with VD had a higher risk of developing ECF.

Osteoporotic vertebral deformity with endplate/cortex fracture is associated with higher further vertebral fracture risk: the Ms. OS (Hong Kong) study results.

Compared with vertebrae without deformity, vertebrae with mild/moderate deformity have a higher risk of endplate or/and cortex fracture (ecf). Compared with subjects without ecf, subjects with ecf are at a higher risk of short-term (4-year period) deformity progression and new incident deformity. INTRODUCTION: The progression and incidence of osteoporotic vertebral deformity/fracture (VD/VF) in elderly Chinese females remain not well documented. METHODS: Spine radiographs of 1533 Chinese females with baseline and year-4 follow-up (mean age 75.7 years) were evaluated according to Genant's VD criteria and endplate/cortex fracture (non-existent: ecf0 or existent: ecf1). Grade-2 VDs were divided into mild (vd2m, 25-34% height loss) and severe (vd2s, 34-40% height loss) subgroups. According to their VD/VF, subjects were graded into seven categories: vd0/ecf0, vd1/ecf0, vd2m/ecf0, vd1/ecf1, vd2m/ecf1, vd2s/ecf1, and vd3/ecf1. With an existing VD, a further height loss of ≥ 15% was a VD progression. A new incident VD was a change from grade-0 to grade-2/3 or to grade-1 with ≥ 10% height loss. RESULTS: Of subjects with Genant's grades 0, - 1, - 2, and - 3 VD, at follow-up, 4.6%, 8%, 10.6%, and 28.9% had at least one VD progression or new incident VD respectively. Among the three ecf0 groups, there was no difference in VD progression or new VD; while there was a significant difference in new ecf incidence, with vd0/ecf0 being lowest and vd2m/ecf0 being highest. Vd1/ecf0 and vd2m/ecf0 vertebrae had a higher risk of turning to ecf1 than vd0/ecf0 vertebrae. If vd1/ecf0 and vd2m/ecf0 subjects were combined together (range 20-34% height loss) to compare with vd1/ecf1 and vd2m/ecf1 subjects, the latter had significantly higher VD progression and new VD rates. CONCLUSION: Vertebrae with grade-1/2 VDs had a higher risk of developing ECF. Subjects with pre-existing ECFs had a higher risk of worsening or new vertebral deformities.

Prevalence and risk factors of radiographic vertebral fractures in elderly Chinese men and women: results of Mr. OS (Hong Kong) and Ms. OS (Hong Kong) studies.

UNLABELLED: This study investigated the prevalence of radiographic vertebral fractures using Genant's semiquantitative (SQ) scoring system in elderly Chinese men (n = 2,000; mean age, 72.4 years) and women (n = 2,000; mean age, 72.6 years). Vertebral deformities had similar prevalence in elderly men (14.9 %) and women (16.5 %). Majority of the deformities in men were mild (9.9 %, grade = 1). The prevalence of vertebral fractures (grade ≥ 2) was 5.0 % among men and 12.1 % among women. INTRODUCTION: Vertebral fracture is a serious consequence of osteoporosis and is often under-diagnosed. Researches on different ethnicities and territories to estimate the prevalence of vertebral fractures and to identify the risk factors are necessary. METHODS: Mr. OS (Hong Kong) and Ms. OS (Hong Kong) represent the first large-scale cohort studies ever conducted on bone health in elderly Chinese men (n = 2,000) and women (n = 2,000). The current study investigated the prevalence of radiographic vertebral fractures in these subjects using Genant's SQ scoring system and identified risk factors for vertebral fractures. RESULTS: The radiographs of all men (mean age, 72.4 years) and women (mean age, 72.6 years) were obtained. Six hundred twenty-seven subjects (15.7 %) had at least one vertebral deformity (SQ grade ≥ 1), including 297 men (14.9 %) and 330 women (16.5 %, p = 0.151). Three hundred forty-two participants (8.6 %) were defined as having at least one vertebra fracture (SQ grade ≥ 2), consisted of 100 men (5.0 %) and 242 women (12.1 %, p < 0.001). Older age, lower bone mineral density, lower physical activity, lower grip strength, fracture history, and low back pain were significantly associated with higher vertebral fracture rate for both men and women. CONCLUSION: Vertebral deformity had similar prevalence in older men and women, while vertebral fracture was more common in women. Majority of deformities in men was mild. The vertebral deformity prevalence of women from this study is similar to previous reports of other East Asian women and Latin American women.

The volumetric relationship of white matter lesion and contrast-enhanced lesion in delayed radiation brain injury: an MRI-based study.

PURPOSE: This study investigated the volumetric relationship of white matter lesion (WML) and contrast-enhanced lesion (CEL) in delayed radiation brain injury (RBI) during the course of evolution. MATERIALS AND METHODS: MRI results in 45 patients with RBI after receiving radiation for nasopharyngeal carcinoma were analyzed. In total there were 75 lobes with RBI and 114 MRI examinations in this study. WML and CEL lesion volumes were measured. The lesion volume change of less than 5% or 0.25 cm(3) was regarded as being static. RESULTS: The average WML volume was 16.33 cm(3) (ranging 0.11 cm(3) to 102.83 cm(3)), and the average CEL volume was 3.15 cm(3) (ranging 0.03 cm(3) to 27.85 cm(3)). WML was larger than CEL in 164 measurements, and CEL was larger than WML in 10 measurements. In 64.3% follow-ups WML and CEL evolved in the same pattern; and in most follow-ups (93.8%) WML and CEL did not evolve in the opposite directions. A larger WML volume tended to have a larger CEL volume though this relationship was not linear. CONCLUSION: Evolution of WML and CEL tended to follow the same pattern. WML tended to be larger than CEL, and larger WML tended to be associated with larger CEL.

Relationship between gender, bone mineral density, and disc degeneration in the lumbar spine: a study in elderly subjects using an eight-level MRI-based disc degeneration grading system.

UNLABELLED: The study cohort comprised 196 females and 163 males. Lumbar spine bone mineral density (BMD) and magnetic resonance imaging (MRI) were acquired. Females had more severe disc degeneration than males. Lumbar spine lower BMD was associated with less severe disc degeneration. Lumbar disc spaces were more likely to be narrower when vertebral BMD was higher. INTRODUCTION: The purpose of this paper is to study the relationship between gender, BMD, and disc degeneration in the lumbar spine. METHODS: The study cohort comprised 196 females and 163 males (age range 67-89 years) with no age difference between the two groups. Lumbar spine BMD was measured with dual X-ray densitometry, and MRI was acquired at 1.5 T. A subgroup of 48 males had additional lumbar vertebral quantitative computerized tomography densitometry. Lumbar disc degeneration was assessed using a MRI-based eight-level grading system. RESULTS: Female subjects had more severe disc degeneration than male subjects. After removing age effect, a positive trend was observed between T-score and severity of lumbar disc degeneration. This was significant in female subjects while not significant in male subjects. Lumbar disc spaces were more likely to be narrowed when vertebral BMD was higher. These observations were more significant in the midlumbar region (L3/4 and L4/5) and less so at the thoracolumbar junction. CONCLUSION: Female subjects tended to have slightly more severe lumbar disc degeneration than male subjects. Lower lumbar spine BMD was associated with less severe disc degeneration.

Tissue characterization using terahertz pulsed imaging in reflection geometry.

Terahertz pulsed imaging (TPI) is a non-ionizing and non-destructive imaging technique that has been recently used to study a wide range of biological materials. The severe attenuation of terahertz radiation in samples with high water content means that biological samples need to be very thin if they are to be measured in transmission geometry. To overcome this limitation, samples could be measured in reflection geometry and this is the most feasible way in which TPI could be performed in a clinical setting. In this study, we therefore used TPI in reflection geometry to characterize the terahertz properties of several organ samples freshly harvested from laboratory rats. We observed differences in the measured time domain responses and determined the frequency-dependent optical properties to characterize the samples further. We found statistically significant differences between the tissue types. These results show that TPI has the potential to accurately differentiate between tissue types non-invasively.

Fluid collection within the synovial sheath of the tendon of the flexor hallus longus muscle in the tarsal joint of rats: an anatomic variant detectable with magnetic resonance imaging.

Magnetic resonance (MR) images of the right tarsal joint of 22 normal male Han:Wistar rats were acquired using a 4.7 T magnet. An intermediate-high signal area associated with the tendon of the flexor hallus longus muscle was noticed in three rats on T2-weighted images. These areas appeared as an intermediate-high signal on lightly T2-weighted images, but appeared as an iso-signal to muscle structure on proton density weighted images. Histology preparations showed that such areas were caused by a sizable fluid collection within the synovial sheath of the tendon of the flexor hallus longus muscle, with all other joint structures appearing normal. This anatomic variant could be potentially regarded as a lesion on T2-weighted MR images, such as inflamed tissue with oedema, especially when the spatial resolution and/or signal-to-noise ratio are not optimal.

Some aspects of rat femorotibial joint microanatomy as demonstrated by high-resolution magnetic resonance imaging.

High-resolution magnetic resonance images (MRI) of the right femorotibial joint of normal Han:Wistar rats were acquired using a 4.7 Tesla magnet and a single-turn solenoid radio frequency coil (built in-house). Some anatomical findings of the rat femorotibial joint, which have not been reported previously using MRI, are described. The separation of patellar ligament and crural fascia was feasible on MRI. This separation would not be seen on images of lower resolution and its presence on high-resolution images could be mistaken for artefact due to the magic angle effect. Band-like fibrous structures exist in the infra-patellar fat pad, which might be mistaken as ligaments within the femorotibial joint. On sagittal MRI a vessel was seen inserted on the central part of the caudal surface of the patellar ligament. Subcutaneous fascia/cutaneous muscles (panniculus carnosus) could also be demonstrated with MRI in the femorotibial joint area.

Liver T1ρ MRI measurement in healthy human subjects at 3 T: a preliminary study with a two-dimensional fast-field echo sequence.

OBJECTIVES: The aim of this study was to explore the technical feasibility of T(1)ρ MRI for the liver, and to determine the normal range of liver T(1)ρ in healthy subjects at clinical 3 T. METHODS: There were 15 healthy volunteers. Three representative axial slices were selected to cut through the upper, middle and lower liver. A rotary echo spin-lock pulse was implemented in a two-dimensional fast-field echo sequence. Spin-lock frequency was 500 Hz, and the spin-lock times of 1, 10, 20, 30, 40 and 50 ms were used for T(1)ρ mapping. The images were acquired slice by slice during breath-holding. Regions of interest (ROIs; n=5) were manually placed on each slice of the liver parenchyma region, excluding artefacts and vessels. The mean value of these ROIs (n=15) was regarded as the liver T(1)ρ value for the subject. Six subjects were scanned once at fasting status; six subjects were scanned once 2 h post meal; three subjects were scanned twice at fasting status; and seven subjects were scanned twice 2 h post meal. RESULTS: When two readers measured the same 10 data sets, the interreader reproducibility (ICC: intraclass correlation coefficient) was 0.955. With the 10 subjects scanned twice, the ICC for scan-rescan reproducibility was 0.764. There was no significant difference for the liver T(1)ρ value at the fasting status (43.08±1.41 ms) and post-meal status (42.97±2.38 ms, p=0.867). Pooling together all the 32 scans in this study, the normal liver T(1)ρ value ranged from 38.6 to 48.3 ms (mean 43.0 ms, median 42.6 ms). CONCLUSION: It is feasible to obtain consistent liver T(1)ρ measurement for human subjects at 3 T.

Compromised perfusion in femoral head in normal rats: distinctive perfusion MRI evidence of contrast washout delay.

OBJECTIVES: The femoral head is prone to osteonecrosis. This study investigated dynamic contrast-enhanced (DCE) MRI contrast washout features of the femoral head and compared the data with data from other bony compartments in normal rats. METHODS: 7-month-old Wistar rats were used. DCE MRI of the right hip (n=18), right knee (n=12) and lumbar spine (n=10) was performed after an intravenous bolus injection of Gd-DOTA (0.3 mmol kg(-1)). Temporal resolution was 0.6 s for hip and spine, and 0.3 s for knee. The total scan duration was 8 min for hip and spine, and 4.5 min for knee. The regions of interest for enhancement measurement included femoral head, proximal femoral diaphysis, distal femoral diaphysis and epiphysis, proximal tibial epiphysis and diaphysis, and lumbar vertebrae L1-5. RESULTS: Femoral head showed no enhancement signal decay during the DCE MRI period, while all other bony compartments showed a contrast washin phase followed by a contrast washout phase. In the knee joint, the contrast washout of the proximal tibia diaphysis was slower that of other bony compartments of the knee. CONCLUSION: Based on the evidence of delayed contrast washout, this study showed that blood perfusion in the femoral head could be compromised in normal rats.

CT and ultrasound features of basal cell adenoma of the parotid gland: a report of 22 cases with pathologic correlation.

BACKGROUND AND PURPOSE: Parotid gland BCA is a rare benign tumor. Only a few studies describing the imaging features of BCA have been published. This study investigated CT and sonography characteristics of BCA of the parotid gland. MATERIALS AND METHODS: Demographics of patients with BCA were evaluated, and lesion characteristics of CT (n = 22) and sonography (n = 20) were reviewed. These cases were grouped into 3 types: type 1 tumors, located at the superficial region of superficial lobe of the parotid gland; type 2 tumors, located at the deeper region of superficial lobe; and type 3 tumors, located in the deep lobe. Imaging findings were correlated with pathology. RESULTS: Sixteen patients (73%) were female and 6 (27%) were male. The mean age was 51.5 years (SD 10.2; range 32-73). The size of the tumors was less than 30 mm. The sizes of type 1, type 2, and type 3 tumors were 11.4 ± 3.29 mm, 19.3 ± 5.44 mm, and 26 ± 3.6 mm, respectively. The CT attenuation increase was 64.5 ± 19 HU on contrast CT. The type 1 tumors were solid (11/11), showed homogeneous or slightly heterogeneous enhancement on CT, and were homogeneously or slightly heterogeneously hypoechoic on sonography. Cystic changes tended to occur in type 2 (7/8) or type 3 (2/3) tumors, which showed obvious heterogeneous attenuation on CT and anechoic on sonography. CONCLUSIONS: The BCA tends to be small and shows early intense enhancement. The solid tumor is common in the superficial region of the parotid gland, and cystic lesions occur mostly in the deeper parts of the superficial lobe or in the deep lobe.

Vertebral body corner oedema vs gadolinium enhancement as biomarkers of active spinal inflammation in ankylosing spondylitis.

OBJECTIVE: To investigate the relative performance of T(2) weighted short tau inversion-recovery (STIR) and fat-suppressed T(1) weighted gadolinium contrast-enhanced sequences in depicting active inflammatory lesions in ankylosing spondylitis (AS). METHODS: Whole-spine MRI was performed on 32 patients with AS, who participated in a clinical trial of infliximab treatment, by STIR and contrast-enhanced sequences at baseline and after 30 weeks. The AS spine MRI-activity (ASspiMRI-a) scoring method was used. The images from these two imaging techniques were evaluated separately by two independent readers. RESULTS: For the pre-treatment lesion status, the intraclass correlation coefficients comparing STIR readings and contrast-enhanced readings were 0.69±0.23 for Reader 1 and 0.65±0.21 for Reader 2. At baseline, the mean ASspiMRI-a score was 15.4% and 17.7% higher for contrast-enhanced images than for STIR images for Reader 1 and Reader 2, respectively. After infliximab treatment, Reader 1 rated an ASspiMRI-a score reduction of 50.8±33.6% and 25.3±35.3% for STIR images and contrast-enhanced images, respectively, whereas Reader 2 rated an ASspiMRI-a score reduction of 42.4±50.4% and 32.9±35.6% for STIR images and contrast-enhanced images, respectively. CONCLUSION: While both contrast-enhanced and STIR sequences showed sensitivity to change over a short period of time after infliximab treatment, these two sequences may reflect different disease mechanisms.

Double contrast percutaneous transhepatic cholangiographic CT in patients with obstructive jaundice: an initial experience of seven cases.

PURPOSE: To explore the technical feasibility of double contrast percutaneous transhepatic cholangiographic CT (DC-PCT-CT) in patients with bile duct obstruction. METHODS: Seven patients with bile duct obstructive diseases were studied, including 5 males and 3 females, ranging in age from 24 yrs to 74 yrs (average: 47.7 yrs). There were 5 cases of hilar cholangiocarcinoma, 1 case of sclerosing cholangitis, and 1 case of malignant transformation of adenoma at the distal end of the common bile duct. PTC was carried out initially, involving injection of 30 ml 4.5-6.0 mgl iohexol. After the bile duct system was filled, CT scan was performed, and further followed by enhanced CT with intravenous injection of 300 mgl/ml contrast agent. Arterial phase, venous phase, and parenchymal phase acquisitions were obtained. Raw CT images were viewed and multiplanar reconstruction (MPR), maximum intensity projection (MIP), and volume rendering (VR) image post-processing were performed. RESULTS: DC-PCT-CT was performed successfully and bile duct drainage was carried out. Mild lesion enhancement was demonstrated in three cases in arterial phase, while all seven cases demonstrated enhancement of various degrees in venous phase.The lesions lead to track-like, asymmetrical or irregular bile duct obstructive narrowing, and in one case intra-luminal filling defect. Reliable diagnosis was suggested in all cases. MPR, MIP and VR images were useful in demonstrating precise lesion location and for surgical planning. CONCLUSION: In patients with bile duct obstruction, DC-PTC-CT is a feasible technique offering both important diagnostic value and drainage application.

How would composite traditional Chinese medicine protect the brain--an example of the composite formula "Pien Tze Huang".

Chinese medicine has a long history of several thousand years. The main form of Traditional Chinese Medicine (TCM) is composite, i.e. a mixture of up to 10 medicinal products. Thus a composite prescription of 4-5 kinds of Chinese medicinal products may contain several hundred kinds of chemical composition. The active ingredients and clinical efficacy of which are difficult to characterize. We aim to review the Chinese literature of TCMs with neuroprotective effects. We illustrate with our study on Pien Tze Huang (PZH) the use of in vivo tests in the study of composite TCM. Our results show evidence that PZH might have neuropreventive effects in rats.

Medical imaging in pharmaceutical clinical trials: what radiologists should know.

The role of medical imaging in pharmaceutical clinical trials includes identification of likely responders; detection and diagnosis of lesions and evaluation of their severity; and therapy monitoring and follow-up. Nuclear imaging techniques such as PET can be used to monitor drug pharmacokinetics and distribution and study specific molecular endpoints. In assessing drug efficacy, imaging biomarkers and imaging surrogate endpoints can not only be more objective and faster to measure than clinical outcomes, but also allow small group sizes, quick results and good statistical power. In this article some basic principles of drug clinical development are explained. Study design, image reading and quantitative image processing in clinical trials with imaging components are discussed.